Aromatic hydrocarbons like naphthalene are common environmental pollutants of petrochemical waste. Microorganisms have been exploited since long back to clean up such pollutants by converting them in to either nontoxic or less toxic aromatic or aliphatic compounds. A bacterial strain have been isolated from oil sludge of Guwahati Refinery, Assam and was identified as Staphylococcus pasteuri RD2 (NCBI accession number MG680735) through 16srDNA sequence analysis and molecular phylogeny. The bacterial strain transforms Naphthalene, a common hazardous aromatic hydrocarbon found in petrochemical waste, into a number of less hazardous aliphatic hydrocarbons. Detection of compounds such as Decane, Dodecane, tetradecane, Hexadecane, Eicosane, and heptane by GC-MS analysis of naphthalene enrichment culture broth suggested that the bacterial strain was able to transform naphthalene in to different aliphatic hydrocarbons with less toxicity and having chain length of C7 to C20. It has also been depicted a pathway to obtain aliphatic hydrocarbons with higher caloric value from aromatic hydrocarbon waste.